Methods and Devices for Controlling the Size of Emphysematous Bullae

ABSTRACT

An implantable device for control over the size of emphysematous bullae in a lung, including: an elongated central region having a fixed axial length; a first end including a first anchor; and a second end including a second anchor.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/026,174, filed Jul. 18, 2014, the entire contents of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to implantable devices for achievingcontrol over the size of emphysematous bullae during respiration. Thedevice includes an elongated member having a fixed length, with at leastone anchor on each end of the elongated member for implantation into thelung.

BACKGROUND

Emphysema is a form of chronic obstructive pulmonary disease (COPD) thatis defined by abnormal and permanent enlargement of the airspaces distalto the terminal bronchioles and is associated with destruction of thealveolar walls. The destruction of alveolar walls causes loss of elasticrecoil, early airway closure during exhalation, and air trapping in thedistal air spaces. Alveolar wall destruction with formation ofemphysematous blebs and bullae leads to loss of gas exchanging surface(also known as increased physiologic dead space). In addition, airtrapping and hyperinflation press the diaphragm into a flatconfiguration, rather than its normal domed shape, and place all themuscles of respiration at a mechanical overstretch disadvantage. Incombination, these processes lead to refractory dyspnea.

Lung volume reduction surgery (LVRS) is a surgical treatment forpatients with advanced emphysema whose dyspnea is poorly controlled withthe usual therapies (e.g., short and long acting bronchodilators,inhaled glucocorticoids, supplemental oxygen, and pulmonaryrehabilitation). LVRS entails reducing the lung volume by wedgeexcisions of emphysematous tissue. However, surgical morbidity is highand non-pulmonary comorbidities may preclude surgery. Bronchoscopic lungvolume reduction (BLVR) refers to techniques developed to treathyperinflation due to emphysema via a flexible bronchoscope.

During the past few years, there has been great interest inbronchoscopic lung volume reduction using different designs of one-wayvalves as an alternative to lung volume reduction surgery. However, theefficacy of these treatments is limited by both the presence ofcollateral airflow from adjacent segments, which inhibits the volumereduction of the treated lobe, and the technical difficulty ofaccurately placing these one-way valves in difficult airways anatomy.However, some valve results showed that the patients with heterogeneousemphysema will not benefit from treatment with one-way valves,indicating the need for BLVR treatments that work independently ofcollateral flow and are less reliant on the very accurate placement ofan air sealing device.

One previous attempt relied upon the use of LVR coils made frompreformed wire, where the coil is delivered into subsegmental airwaysand recovers to a predetermined shape upon deployment. Additional coilsare implanted as necessary, with each coil reverting to its twisted,entangled shape. The problem with this approach is that the coils mayalso entrap or ensnare portions of the lung parenchyma that still haveregions or pockets of functional respiration within the bullae. There ispresently a need to have a device that can prevent the formation ofbullae without the necessity of lung volume reduction. A device that canprevent bullae formation without eliminating remnants of functional lungparenchyma is needed.

SUMMARY

The invention is related to an implantable device for control over thesize of emphysematous bullae in a lung, including: an elongated centralregion having a fixed axial length; a first end including a firstanchor; and a second end including a second anchor.

The invention also includes an assembly including the implantable deviceand a deployment device for placing the implantable device in a desiredlocation.

The invention also includes a method of delivering the implantabledevice, including the steps of aligning the first anchor to a targetsite while the implantable device is at least partially placed within adeployment device, deploying the first anchor such that it engages afirst region of the lung, pulling the first anchor in a proximaldirection towards the second anchor, and releasing the second anchorsuch that it engages a second region of the lung.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1A-1E show various stages of deployment of a device.

FIG. 2 shows an alternate device in a deployed state.

FIG. 3 shows an alternate device in a deployed state.

FIG. 4 shows an alternate device in a deployed state.

FIG. 5 shows an alternate device in a deployed state.

FIG. 6 shows an alternate device with attachment regions in a deployedstate.

FIGS. 7A-7C show various stages of deployment of an alternative device.

FIG. 8 shows an alternate device in a deployed state.

FIG. 9 shows an alternate device in a deployed state.

FIG. 10 shows an alternate device in a deployed state.

FIG. 11 shows an alternate device in a deployed state.

FIG. 12 shows an alternate device in a deployed state.

FIGS. 13A-13C show various stages of deployment of a device within alung.

FIGS. 14A-14B show an alternate embodiment of a device with radiallyexpanding fixation elements.

DETAILED DESCRIPTION

The present invention relates to an implantable device suitable toachieve Bronchoscopic lung volume reduction (BLVR) in a patient. Thepatient may be a mammal, such as a human. The implantable device issuitably delivered by a clinician, such as a surgeon. As used herein,the individual implanting the device will be referred to as the“clinician” or “user”, and the location of implantation will be referredto as the “target site”. The target site is desirably one or more spacesin the lung of the patient, such as a bronchiole or other region in thelung.

The device is generally an elongated device, having a first end, secondend, and a central region. The central region is generally cylindricalin shape, and is desirably a semi-rigid material such that it will notbe bent or flexed during normal respiration. As will be described below,the first and second ends may include flexible elements or shape memoryelements. The relative rigidity of the elements is such that the firstand second ends are more flexible than the central region. The elongatedcentral region has a fixed length and remains substantially straightbefore, during and after implantation. The use of a straight, fixedlength central region allows for implantation without folding of lungtissue and unnecessary exclusion of functional parenchyma fromrespiration. Different length devices are contemplated, to achievedifferent levels of reduction. Different diameter central regions canalso be utilized to closely match the region of the lung targeted fortreatment. For example, a smaller emphysematous region can be treatedwith a device having a smaller diameter central region and a largeremphysematous region could be treated with a device having a largerdiameter. These decisions are made by the clinician (e.g., aninterventional pulmonologist, physician or surgeon) and are based on anumber of factors, including the size of the emphysematous region, thediameter of the bronchi used in deployment, and how distal theemphysematous region is in the respiratory tree.

At the first end and the second end is at least one anchor. The anchoris designed to be deployed within a region of the lung, such as abronchiole, and after implantation, the anchor is securely implantedwithin the region into which it is implanted. It may be desirable thatthe anchor be free of traumatic elements, such as tissue piercingelements, although piercing elements may be used in some configurations.

In use, the clinician inserts the device through a suitable implantationmeans or deployment device, such as a catheter or bronchoscope, aligningthe first end with the target site. The first end may be referred to asthe distal end, since it is located distally from the clinician (ascompared to the second end). In that respect, the second end may bereferred to as the proximal end, since it is located more proximally tothe clinician than the first end. After aligning the first end, thefirst end is released from the deployment device, where it engages thetarget site of the lung, including a bronchiole. The device is thenpulled or compressed proximally. Since the first end is now securelyengaged with tissue, pulling the device results in the section of thelung tissue being pulled or compressed or collapsed proximally. When thelung has been pulled or compressed to a desired length, the second endmay be released from the deployment device, where it secures itself to asecond region of the lung. The clinician performing the procedure willtry to pull the device proximally to a point where the volume of thelung has been reduced to a desired dimension to allow for normal,better, or less restricted breathing. This is ascertained by imagingtechniques known to one of ordinary skill in the art. Thus, the intentis not necessarily to cause complete collapse of the emphysematousregion, but to reduce its volume to a size that will allow any remnantsof functional alveoli to participate in respiration as well as preventthe excessive expansion seen in the original, untreated bullae.

Given the rigid, fixed length central region, the lung volume will bereduced to the extent that the lung tissue is pulled or compressedproximally, without the need for tethering, locking, or other means tosecure the implanted device's length. Previous methods have relied uponthe use of a string or other tethering device, which is used to pullmultiple anchors. When such tethering devices are used, there isrequired a locking or other securement means when the implanted devicehas been pulled to a sufficient degree. With the present invention, thedevice has a fixed length, and therefore no adjustment of the devicelength, or securement of the device's length is required. The length ofthe implanted device is known, and there is greater assurance to theclinician of the implanted device's security.

Thus, the invention includes a device for controlling the volume of aportion of a lung, the device including an elongated central body havinga fixed length, and the device having a proximal end and a distal end.The device includes at least one anchor at the proximal end of the bodyand at least one anchor at the distal end of the body. The anchors maytake differing configurations, as will be described below. For example,in one configuration, the anchors have deformable members having apositioning configuration in a collapsed state and an anchoringconfiguration in an expanded state. The anchors include at least oneengagement feature with an attachment means, to secure the anchor in thedeployed position. The device may include non-tissue piercing engagementfeature, and in some embodiments, the device may be removable afterdeployment.

Thus, the device includes, in its broadest sense, three components: acentral region, a first end and a second end. The three components willnow be described. The elongated central region may be a wire or mayinclude a plurality of wires connected to each other at at least oneconnection point. The elongated central region is desirablysubstantially rigid, such that it will maintain its shape and lengthbefore, during and after deployment of the device. The central regionmay include imaging markers, such as radiopaque markers or fluorescentmarkers at one or more regions of the central region.

The elongated central region may have any cross-section desired, such ascircular, triangular, square or rectangular. If the central region ismade of a plurality of elongated elements, those elements may bearranged in a tight configuration, or may be arranged in a circularconfiguration with a hollow interior. The elongated central region mayhave any axial length (measured from first end to second end) desired,including about 1 cm to about 5 cm length, or alternatively about 1 toabout 3 cm length, and about 0.1 mm to about 2 mm diameter or about 0.3mm to about 1 mm in diameter. The central region may be solid or mayhave a hollow axial interior (e.g., a tube).

The first end and the second end include at least one anchor. The anchoror anchors at the first end and the second end may be the same or theymay be different. The anchors may be formed from the same material asthe elongated central body, or they may be separate components that aresecured to the central body. In some embodiments, the elongated centralbody is a unitary structure, and the anchors at the first and second endare formed by longitudinal segments formed in the central body at leastat one end thereof by longitudinal cuts. In other embodiments, thecentral body may include a plurality of linear members joined lengthwiseat at least one connection point, and the anchors are formed from thelinear members at the first and the second ends.

The anchors at the first and/or second ends may have any desiredconfiguration, where the anchors are sized and shaped to be deployedwithin the target site and be secured there via tissue engaging orcontacting feature or features. As noted above, the anchors and thetissue-contacting feature at the first and second ends may be the sameor may be different. The tissue-contacting (or tissue-engaging) featuresmay include features such as barbs, balls, roughened surfaces, hingedarms, shape memory materials, and combinations thereof.

In one embodiment, the first and second ends include shape memorymaterials, where in a collapsed state the anchors extend axially alongthe axial length of the central elongated region, but when released fromthe collapsed state, the anchors curl or move to be substantiallyperpendicular to the axis, or to be facing the opposite axial direction.An anchor may be curled in the shape of a semi-circular orsemi-elliptical configuration, approximating a segment of a circle orellipse to any degree desired. The degree of curvature of the anchorsmay be from about 25 degrees to about 180 degrees, or from about 45degrees to about 120 degrees. In some embodiments, an anchor may have adegree of curvature of about 60 to about 90 degrees.

For example, FIGS. 1A-1E depict various stages of deployment of a devicefrom a catheter. In this embodiment, the device 10 includes a centralbody 20, which is elongated and includes a distal end 30 and a proximalend 40. The central body 20 maintains its axial length (defined as thelength between distal end 30 and proximal end 40) during implantationand after implantation. The device includes and anchor at the distal end30, and in this embodiment, the anchor includes a first shape memoryelement 50′ and a second shape memory element 50″. The device in thisembodiment includes an anchor at the proximal end 40, as well, where theanchor at the proximal end 40 includes a first shape memory element 60′and second shape memory element 60″. As depicted in FIGS. 1A-1E, theshape memory elements (50, 60) expand outward approximately to about 45degrees. Also, in this embodiment, the shape memory elements 50, 60include ball-like members on their ends, which are intended to reducetrauma and allow for repositioning if desired. Other ends as describedabove may be used. Further, more or less shape memory elements may beused at each end, if desired.

Before deployment, the device 10 is housed within a catheter 70, orother elongated device shaped and sized to house the device 10. Thedevice 10 is housed within the catheter 70 in such a fashion that theshape memory elements 50, 60 are compressed. Within the catheter 70 is apositioning element 80, which is disposed at the proximal end 40 of thedevice 10. The positioning element 80 may include a central opening 90,if desired. The proximal end 40 of the device 10 includes an engagementmember 100 or other device, which is removably secured to an attachment110 located at the distal end of the positioning element. The engagementmember 100 may be a string or tether with a hook or eyelet at theproximal end, where the hook or eyelet engages with the attachment 110of the positioning member 80. For example, the engagement member 100 mayinclude an eyelet or ring, which is fitted onto a hook of the attachment110. Removal of the engagement member 100 from the attachment 110 may beachieved by sliding the eyelet or ring of the engagement member 100 offof the attachment 110. In some embodiments, the engagement member 100may have a magnetized end, which may be secured to an attractive elementon the attachment 110. Other removable connections for the engagementmember 100 and attachment 110 may be used as desired.

As seen in FIG. 1B, the catheter 70 is pulled proximally, while thepositioning member is maintained in its position. The positioning memberrestricts the device 10 from being pulled with the catheter 70, and thusthe distal end 30 of the device 10 is released from the catheter 70.Upon release from the catheter 70, the first shape memory elements 50′,50″ are allowed to expand to their desired position. When the device 10is implanted into a body or organ, the expansion of the first shapememory elements 50′, 50″ allows the shape memory elements 50′, 50″ to besecured into openings in the tissue of the body or organ. At this point,the elements at the proximal end 40 of the device 10 have not beenreleased from the catheter 70. If desired, the catheter may be advanceddistally again, compressing the first shape memory elements 50′, 50″,and allowing re-positioning of the device 10.

If the device 10 is positioned properly, the catheter 70 may continue tobe withdrawn proximally, as seen in FIG. 1C, thereby releasing thesecond shape memory elements 60′, 60″. Also as seen in this Figure, thesecond shape memory elements 60′, 60″ include ball-like members on theirends, but other ends described above may be used. It is desired thatdistal engagement members, such as shape memory elements 50′, 50″ at thedistal end 30 are configured to engage tissue and hold tissue whenpulled in the proximal direction. Similarly, it is desired that proximaltissue-engaging or tissue-contacting members, such as shape memoryelements 60′, 60″ at the proximal end 40 are configured to engage tissueand hold tissue when pulled in the distal direction.

At this stage, the anchors of the device 10 have been released and arecapable of grasping tissue, enabling the device 10 to be pulled and pulltissue in an opposite direction (e.g., distal anchors can pull tissueproximally and vice versa). The positioning member 80 is still securedto the device 10, since the engagement member 100 is still secured tothe attachment 110 of the positioning member. Since the engagementmember 100 is secured to the positioning member 80, the positioningmember 80 may be pulled proximally, thereby pulling the distal end 30 ofthe device 10 in the proximal direction, and pulling any tissue intowhich the anchor of the distal end 30 of the device is secured, as well.The user may pull the distal end 30 (and also any tissue securedthereto) to any desired compressed length.

When the device is positioned and pulled to the desired length, theengagement feature 100 may be released from the attachment 110. In oneembodiment, the distal end 85 of the positioning member 80 may beopened, allowing release of the engagement feature 100 (seen in FIG.1D). The engagement feature 100 may be severed from the attachment 110,in some embodiments. FIG. 1E shows the device 10 after it has beenreleased from the catheter 70 and the engagement feature 100 has beenreleased and/or severed from the attachment 110. If desired, theengagement feature 100 may be severed at a location closer to thecentral body 20.

FIG. 2 depicts an alternate device as released from a delivery device,such as a catheter, but in this Figure, the shape memory elements have agreater degree of curvature (a smaller radius) in the absence of forcethereon, such as after deployment. As can be seen, the device includesthe elongated central body 120, with distal end 130 and proximal end140, as described above. The distal end 130 includes at least one, anddesirably at least two engagement members, which may be shape memoryelements 150′, 150″. Proximal end 140 may include at least one, anddesirably at least two engagement members, which may be shape memoryelements 160′, 160″. Engagement members may be the same or may bedifferent from each other. It is desired that distal engagement members,such as shape memory elements 150′, 150″ at the distal end 130 areconfigured to engage tissue and hold tissue when pulled in the proximaldirection. Similarly, it is desired that proximal engagement members,such as shape memory elements 160′, 160″ at the proximal end 140 areconfigured to engage tissue and hold tissue when pulled in the distaldirection. In this fashion, anchors or tissue engaging features cananchor to the tissue into which they are implanted, such that the devicecan be pulled in the opposite direction and pull the tissue along withit. That is, distal anchors enable tissue to be pulled proximally andvice versa. Further, tissue-engaging features such as anchors enableholding of the tissue in place, such as in a compressed state, afterfull deployment of the device.

The device in FIG. 2 may be released from the delivery device, such ascatheter 170, having positioning member 180 with a distal end 185 andcentral opening 190. The catheter may have an attachment 210 securedthereto, to which an engagement feature 200 may be secured duringimplantation and positioning of the device.

If a plurality of shape memory members or other engagement feature areused as an anchor, the shape memory members may take various forms andconfigurations. For example, one member may have a different size,shape, degree of curvature, or end feature than another member at thesame end or at a different end. By way of non-limiting example, FIGS.3-5 show several suitable configurations that would be useful in thepresent invention. FIG. 3, for example, shows a device with elongatedcentral body 300 defined by distal end 310 and proximal end 320, with aplurality of shape memory elements 330′, 330″ at the distal end andplurality of shape memory elements 340′, 340″ at the proximal end. Inthis embodiment, it can be seen that each end has at least twodifferently configured members. At the distal end 310, shape memoryelement 330′ has a broader curvature than shape memory element 330″. Abroader curvature may aid in grasping a larger volume of tissue in use.In this embodiment, shape memory element 340′ has a greater overalllength than shape memory element 340″, such that the base of its curveextends more proximal (with respect to the central axis of the device)and the end of the element 340′ extends more distal than the secondshape memory element 340″.

In FIG. 4, each end (distal end 410 and proximal end 420, respectively)has a pair of substantially identical elements, but the elements at thedistal end 410 (elements 430′, 430″) differ in configuration than theelements at the proximal end 420 (elements 440′, 440″).

FIG. 5 depicts a configuration whereby the elements at one end aredisplaced from each other axially. That is, the device includes distalend 510 with at least two shape memory elements 530′, 530″. Shape memoryelement 530′ extends from the device at a different axial location thanshape memory element 530″, and each has an end that is off-set from eachother with respect to the central axis of the device.

It is desirable that each of the aforementioned designs andconfigurations includes an engagement feature (350, 450, 550) withsecurement end (360, 460, 560), where the securement end can beremovably secured to a delivery device, to facilitate implantation andplacement of the device in the proper tissue region. As can be seen, theanchors on each end may be the same or different from each other, oreach anchor may have a plurality of gripping or tissue-contactingfeature, where each tissue contacting feature is different from othertissue-contacting features at the same end or at the opposing end. Theshape memory elements may have a number of different physicalcharacteristics, include varying lengths, curvature radii, axialdisplacement, and combinations thereof.

FIG. 6 depicts an embodiment of an implantable device that includes aplurality of elongated elements 605 forming the elongated central body600, where the central body 600 is axially defined by distal end 660 andproximal end 670. In this aspect, each end (distal and proximal)includes at least one, and desirably a plurality of anchor members 620,630. To maintain the multiple elongated elements 605 secured to eachother, there may be at least one and more desirably a plurality ofconnection points 610 in the device. As seen in FIG. 6, there are threeconnection points, with a central connection point 610, a distalconnection point 610′ and a proximal connection point 610″. More or lessconnection points may be used as desired. For example, there may be fromone to about 10 points of connection along the central body 600. Thepoints of connection 610 may include, for example, welded regions, tiedregions, banded regions, and the like. The use of a plurality ofelongated elements 605 may be useful in improving strength of thedevice, but also allowing a fluid channel through and around the centralbody 600. As with above, the device includes engagement feature 640 andan eyelet or other securing portion 650 to hold the device in thedelivery apparatus until placement is achieved. The engagement feature640 and securing portion 650 may be a hook and eyelet, or they may beattractable portions (such as through a magnet on one or both), or anyother removable or severable attachment means.

FIGS. 7A-7C show alternate embodiments, which include anchoring membersthat have a different configuration than the embodiments seen above. Ascan be seen in these Figures, the anchors may include at least onehinged arm, where the hinged arm faces towards the opposite end but isnot curved at the angles described above. For example, if a hinged armis placed at the first end, the hinged arm may face axially towards thesecond end. The hinged arm may have any angle (as measured between thelongitudinal axis of the central body and the hinged arm) of from about0 to about 50 degrees in a collapsed state, and about 10 to about 90degrees in an extended state. As seen in FIGS. 7A-7C, the hinged arm740, 750 may extend from the central body 700 at the proximal end 720,distal end 710, or therebetween. Any number of hinged arms may be usefulin the present invention, such as from 1 to about 10. As noted above,the end of the hinged arm, as with the shape memory elements above, mayhave any feature, including atraumatic features such as balls or bluntedends. Alternatively, it may include a piercing or tissue-penetratingelement, such as a needle, barb, hook or other element.

Deployment of a device including a first end having hinged arms and asecond end including curling shape memory anchors is seen in FIGS.7A-7C. FIG. 7A depicts the device in a collapsed state, as it iscontained within a delivery device 760, such as a catheter. The deliverydevice 760 includes an outer sheath and a placement device 770, withelongated central region 780. The placement device 770 includes a distalend, at which the device is secured. Securement may be via engagementfeature 790 and attachment 800, as described above. The device incollapsed state is introduced into the body into the tissue in which thedevice is to be implanted. The catheter 760 sheath is withdrawn in theproximal direction, allowing the distal end 710, with its anchor(s) 730,to be free from the catheter's constraint. In this embodiment, the shapememory elements 730 are free to take the unencumbered shape, such as thevarious configurations described above. The shape memory elements 730engage tissue into which the device is implanted, and the device may bepulled proximally (such as by pulling on the attachment 800, which pullsthe engagement feature 790, pulling the entire device proximally). Thispulls or compresses or collapses tissue along with the device, given theshape and configuration of the shape memory elements 730 at the distalend 710.

Once the distal end 710 is placed and tissue is pulled (if desired), thecatheter 760 is pulled further proximally while the device is held inplace, revealing any other anchors on device body 700. As seen in FIG.7C, upon retraction of the catheter 760 sheath, anchor members (here,hinged arms 740, 750) are freed from the constraint of the catheter 760and allowed to expand to their unencumbered configuration. Since thedevice is still secured to the catheter 760 and placement member 770,the device may be pulled proximally or may be pushed distally. Since theanchors in the device (e.g., 730, 740, 750) are expanded and allowed toengage tissue, pulling and/or pushing the device moves and compressesthe respective tissue. Tissue may be collapsed by pulling the deviceproximally, and upon release of the proximal anchors (740, 750),collapsed tissue between the distal end 710 and proximal end 720 may betrapped and held in the collapsed state. In addition, if non-traumaticends are used, the catheter 760 sheath may be placed back over thedevice, collapsing any anchors and freeing the tissue held therein, andthe device may be moved or replaced into a different position.

The device may be moved into final position, and the engagement feature790 may be severed or otherwise disconnected or released.

As can be seen in the above Figures, the anchors or othertissue-engaging or tissue-contacting features may be atraumatic and/ornon-tissue piercing. The ends may be rounded, ball-like ends as seenabove, or they may simply be smooth, blunted non-piercing ends. The tipof the engagement feature may be, for example, a hook, a ring, a ball,an ellipsoid, a disk, or a tab. The tip of the anchor engagement featuremay have a thickness that is greater than the anchor wire or centralbody thickness. It is contemplated, however, that the ends of theengagement feature may include a tissue engaging or tissue piercingelement, if such anchoring is desired. In such embodiments, theconfigurations described and seen above may have at least one tissuepiercing end. The anchors may include only one engagement feature (i.e.,one hinged portion) or they may include a plurality of engagementfeature (i.e., two or more hinged portions).

Further, the anchors may have various combinations of piercing,non-piercing, hinge, curling, and other tissue-engaging or tissuecontacting features. Thus, a device may have, for example, a first endthat includes two curled non-piercing tissue-engaging or tissuecontacting features, and a second end that has one curled non-piercingtissue-engaging or tissue contacting features. Another device mayinclude a first end having at least one curled non-piercingtissue-engaging or tissue contacting features, while the second endincludes at least one hinged, tissue-piercing tissue-engaging or tissuecontacting features. In some embodiments, the device may include a firstend having at least one curled tissue-engaging or tissue contactingfeatures and at least one hinged tissue-engaging or tissue contactingfeatures, and a second end having at least one hinged tissue-engaging ortissue contacting features and/or at least one curled tissue-engaging ortissue contacting features.

For example, FIGS. 8-12 depict various configurations that includecombinations of curved members, hinged members, penetrating members andnon-penetrating members. Each of these figures includes the central bodyaxially defined by a proximal end and distal end, with anchor members atthe proximal and distal ends. Each also includes an engagement featureat the proximal end, which is to be secured to an attachment in adelivery device for placement and pulling the device in tissue. FIG. 8,for example, shows a plurality of hooked shape memory elements, with atleast two elements 930′, 930″ at the distal end 910, and at least twoelements 940′, 940″ at the proximal end 920. At the end of each of thedistal elements 930′, 930″, there is a tissue-penetrating hook 950 orother piercing member. At the end of the proximal elements 940′, 940″,there is also a tissue penetrating hook 960 or other piercing member.FIG. 9 shows hinged arms (1010, 1020) with tissue-penetrating elements(1030, 1040) on each hinged arm. FIG. 10 shows hinged arms 1110, 1120with ends that are non-tissue-penetrating (1130, 1140). FIG. 11 shows apair of distal end elements 1210′, 1210″, each of which has a hook orbarb 1230 at its end. In this embodiment, the distal end elements 1210may extend substantially distally, while the hook or barb 1230 may facethe proximal end (allowing it to engage tissue and enabling it to pullsuch tissue proximally). FIG. 12 shows a proximal end with four hingedarms 1350, 1340, and a distal end with a multi-angled configuration. Themulti angled configuration in this embodiment has anchors 1310′, 1310″each with a bend 1320 and an end 1330. The end 1330 faces in theproximal direction, again, allowing for it to engage tissue and allowingthe device to pull such tissue proximally after implantation.

Any combinations of the above anchor configurations may be used. Theanchors may have tissue contacting or tissue engaging features arrangedin any desired configuration including penetrating ends ornon-penetrating ends, rounded curvatures, hinges, longer or shorterlengths, multi-angled configurations, or barbs that face an opposingdirection. In addition, these members or anchors may be disposed ateither axial end of the device, or they may be disposed on the side wallof the elongated body at a more central region than either the distal orproximal end. If multiple tissue contacting or tissue engaging featuresare used, they may each be disposed on the axial end, or they may bedisposed on the side wall of the elongated body. They may be disposedcircumferentially spaced about the body, or they may be offset from eachother. They may be helically disposed or linearly disposed. The anchorsand tissue contacting or tissue engaging features may be disposed at thesame position(s) on the first end as they are on the second end.

The anchor lengths may be any size desired, and in some embodiments, theanchor length may be from about 10% to about 25% to about 50% or up to100% of the axial length of the central elongated body. Anchors at thedistal end may be larger in size, shape, length, or thickness as anchorsat the proximal end, or anchors at the proximal end may be larger insize, shape, length, or thickness as anchors at the distal end, or theymay be the same size, shape, length or thickness.

Delivery of the device may be achieved through a catheter or othersimilar delivery device having a sheath that can hold and compress thedevice in a collapsed state. During delivery, the device and its anchorsare held in a collapsed configuration within the delivery device. Uponalignment of the distal end at the target site within tissue, a pushingmeans may be used to deploy the first end such that it is engaged andsecured to the target site. The pushing means may push the devicedistally, or it may hold the device in place while the outer sheath ismoved proximally. The distal end, and any anchor members thereon, isreleased from the outer sheath, allowing the anchors to take theirunencumbered shape and engage tissue. The device may be pulledproximally, so as to pull the tissue in which the distal end is engaged,and then the catheter sheath may be withdrawn proximally to a greaterextent, releasing any anchors along the central body. Finally, thedevice is fully released from the sheath, and any anchors at theproximal end are released from the catheter sheath. Releasing theproximal end causes any anchors thereon to take their unencumberedconfiguration and secure themselves to the target site tissue at thesite of release.

The device and anchors, with tissue contacting or tissue engagingfeatures, may be disposed and implanted through any desired means,including, for example, a pushing means. Alternatively, they may bedisposed with a grasping device, which includes a connector means or arelease mechanism, such as the release of a sheath or catheter. Thedevice anchors may be implanted by a grasping element having a tether orother type of release. The device may be released through a screw-typedevice, or a hook and loop type of mechanism. It may be desired that thedevice be capable of being retrieved by the deployment mechanism, suchthat it may be removed or replaced if needed. A connector portion of thedeployment device may include a grasping element designed to grasp aportion of one end of the implantable device.

Ultimate release of the device from the delivery device may be achievedby releasing or severing an engagement feature, which is secured to anattachment in the body of the delivery device. For example, theengagement feature may be a tether that is physically connected to thedevice and is secured to an attachment, such as an eyelet or otherfeature in the delivery device. Release may also be achieved byrotational engagement, where rotation of a connector feature disengagesthe connector feature from the implantable device, or by screwengagement, or by release of compression, or any other desired releasemethods.

The present invention includes a method of compressing the volume of aportion of soft tissue, such as a portion of a lung. The devicesdescribed above may be useful in this method. FIGS. 13A-13C show severalsteps of this method. FIG. 13A shows the device as it is being implantedinto a desired region of the lung, with the distal end already releasedfrom the catheter sheath. The desired region into which it is implantedmay be a diseased region of a lung such as an emphysematous bullae, ormay be a healthy region of a lung. FIG. 13B shows the movement of theimplantable device in a proximal direction (direction “A”), pullingtissue engaged with the distal anchor element(s). FIG. 13C shows therelease of the proximal end of the implantable device after the tissuehas been moved proximally. For this description, the implantable deviceincludes an elongated central body 1400, which is axially defined by aproximal end 1420 and distal end 1410, with anchor members on each end.In this description, the distal anchor members 1430′, 1430″ areatraumatic anchors with a 180 degree curvature, and the proximal anchormembers 1440′, 1440″ are similarly atraumatic anchors with a 180 degreecurvature. It is understood that any alternative configurationsdescribed above may be used in this method, but for simplicity and easeof understanding, only this configuration will be used in the followingdescription.

The method first includes the step of identifying the portion of thetissue that is to be compressed. That portion may include, for example,a diseased portion of the lung. The implantable device, which may havethe configurations described above (which generally includes anelongated central region having a central axis, which is defined by aproximal and distal end, each end having an anchor, which may includeone or more shape memory elements) is placed into a deployment device,such as a catheter with a lumen sized to accommodate the device. Whilecontained within the sheath of the catheter, the implantable device isin a collapsed or compressed state, where the anchor elements thereonare in a temporary state of compression under force.

The implantable device is engaged with a positioning member (also knownas a pushing member) while in the deployment device, the positioningmember including an element sized to fit inside the catheter and thepositioning member having a connector attachment adapted to releasablyengage with the implantable device. The connector attachment may besecured to the engagement feature(s) of the implantable device. In oneembodiment, the connector attachment is an eyelet or other threadableelement, and the engagement feature is a tether connected to theproximal end of the implantable device, which can be secured to theconnector attachment. The connector attachment and the tether may bereleasably connected via other means, such as through the use of magnetsor other connection. The positioning member may be at least partiallyenclosed within the outer sheath of the catheter, capable of beingaxially slidable in the proximal or distal directions, and theimplantable device is disposed distally of the positioning member. Thepositioning member and the catheter may be axially slidable ordisplaceable with respect to each other. The positioning member may havean axial opening, into which the engagement feature of the implantabledevice can be placed. The use of an axial opening in the positioningmember allows for a user to grip or otherwise contact the engagementfeature during implantation. It is desired that the proximal end of theimplantable device be at least partially in contacted with the distalend of the positioning member, so as to allow the positioning member topush the implantable device distally or to hold it in place duringimplantation.

The method includes the step of advancing the deployment device into thedesired tissue region, and releasing the distal end of the device fromthe deployment device, thus allowing any anchor elements at the distalend of the implantable device to return to their permanent shape andconfiguration within a target site in the tissue. Release of the distalend may be achieved by holding the device in place by the positioningmember, and sliding the catheter proximally, or it may be achieved byholding the catheter in place and pushing the device distally. Thedistal end of the implantable device is released from the catheter andthe anchor element or elements are free to take their unencumberedshape, as explained above.

The distal anchor element(s), now secured in the target tissue (such aslung parenchyma and distal bronchia wall), as can be seen in FIG. 13A.By pulling the implantable device proximally, the tissue into which thedistal anchor(s) is secured is moved in the proximal direction (A).Arrow B indicates compression of tissue upon pulling device proximally,with shorter length of arrow B indicating tissue is compressed. Based onimaging of the lung obtained by a visual means, such as an endoscope, CTscan, MRI, ultrasound, and the like, a user, such as a physician, maydecide to pull the implantable device more or less proximally until itreaches a point that reduces the emphysematous bullae to the desireddegree. This movement of tissue can be seen in FIG. 13B. Thus, themethod includes the step of compressing a section of tissue by pullingthe implantable device towards a proximal end. Once the tissue has beenpulled to the desired length, the proximal end of the implantable devicecan be positioned in the desired location in the tissue. The proximalend of the implantable device, and any anchor elements thereon, may bereleased from the catheter sheath. As with the distal end, release ofthe proximal end may be achieved by holding the device in place by thepositioning member, and sliding the catheter proximally, or it may beachieved by holding the catheter in place and pushing the implantabledevice distally. The proximal end of the implantable device is releasedfrom the catheter and the anchor element or elements are free to taketheir unencumbered shape, as explained above. If any anchor elements aredisposed along the axial length of the central body, they are releasedsequentially as the catheter is moved proximally with respect to theimplantable device. In some embodiments, the step of pulling theimplantable device proximally after the distal anchor element(s) arereleased need not be performed, such as in the deployment into adeflated lung.

Once proximal end of the implantable device is released from thecatheter and the anchor element or elements are free to take theirunencumbered shape, the anchor elements engage the tissue into whichthey are implanted. Optionally, the implantable device may be moved inany direction, since the device is still secured to the positioningmember by contact and also the attachment is still secured to theengagement feature.

Finally, the method includes the step of disengaging the implantabledevice from the positioning member. Disengaging may include, forexample, severing the engagement feature, untying the engagementfeature, disconnecting magnets or other holding device, or otherwiseseparating the engagement feature from the attachment.

The present invention may include a kit, which includes the implantabledevice as explained above (which includes an elongated central region,and a proximal and distal end, each end having an anchor element), adeployment device, which may include an elongated catheter with a lumensized to accommodate and compress the implantable device into acollapsed state, and a positioning member sized to be slidably fitinside the catheter and having an attachment adapted to releasablyengage with an engagement member of the implantable device. For example,the attachment may be releasably engaged with a proximal and/or distalengagement feature of the device. The various components may be packagedtogether or may be packaged separately. Further, the invention includesan assembly including the implantable device and the deployment device,with the positioning member therewithin.

The anchor elements may be metal or polymeric. In one embodiment, theanchor elements are comprised of nitinol. In one embodiment, the anchorelements have protrusions or roughened surfaces from their outer surfaceto engage surrounding tissue so as to secure them in place, or theanchor elements may be free of tissue-penetrating elements.

The present invention differs from prior attempts using a coiled devicein that the clinician needs only to pull the inventive device proximallyafter the distal anchor is deployed. The amount of pulling or tissuecompression can be at the discretion of the clinician, and is preferablyguided by imaging techniques. In addition, the axial length region ofthe inventive device can be varied, i.e., many lengths can be providedto tailor the procedure to anatomical dimensions and surgical need. Thevarious materials, including the implantable device, may be MRIcompatible.

One embodiment of the invention may include the distal end and proximalend of the implantable device being interconnected by a ratchetingconnector, with adjustability of the implantable device length andadditional tissue compression capability. In another embodiment, thedistal and proximal ends may be connected by a string or tether, suchthat the tether comprises the elongated central body of the implantabledevice. In embodiments where the elongated central body is hollow, astring or tether may be fed through the center of the elongated centralbody for attachment to deployment device. For a hollow tubular centralbody, anchors may be formed from walls of the tubular body, such as byforming axial slits in the tubular body and bending resulting strips ofmaterial forming deployable anchors.

In yet another embodiment, the elongated central body of the device mayinclude or consist of a tensioner spring between the distal anchorelements and the proximal anchor elements. The spring may extend theentire axial distance therebetween or a part of the elongated body. Theuse of a spring may enable further tensioning of the implantable devicejust before releasing the distal anchor elements from the deploymentimplantable device, thus resulting in further compression of tissue, anda spring may offer some lateral deformation mobility or elastic bending.It is preferred, however, that the axial length of the device fromproximal end to distal end remains constant.

There may be included magnetic interactions of deployed anchor elements.In one embodiment, the magnets are rare earth magnets. The anchorelements may be encased within a silicone or other elastomer known to bebiocompatible and stable within the body, i.e., non-resorbable. Thecasing may include a radiopaque material such as barium. In oneembodiment, the encased magnet has pointed edges or barbs on its outersurface so as to engage surrounding tissue such as bronchial wall orlung parenchyma. The implantable devices may be deployed in differentbronchial paths at a point as distal as possible.

In some methods, vacuum may be applied to the region of the lung beingtreated so as to induce the sections of the lung towards one another.

FIGS. 14A-14B show an alternate configuration for an implantable device,which has an elongated central region 2000 with a fixed axial length,the central region 2000 having proximal end 2010 and distal end 2020. Ateach end, there is a fixation element, with proximal fixation element2030 located at the proximal end 2010, and distal fixation element 2040located at the distal end 2020. In this embodiment, the fixationelements 2030, 2040 are radially-expanding elements, which include aseries of shape-memory elements that have a radially-expanding centralregion. In FIG. 14A, it can be seen that the proximal fixation element2030 is expanded, while the distal fixation element 2040 is compressed.Although not seen in this Figure, the distal fixation element 2040 iscompressed through application of some force or energy, such as by beingcompressed in a catheter or deployment tube, as explained above. In someembodiments, the device may be compressed until energy, such as heat orother stimulus, is applied thereto. FIG. 14B shows the distal fixationelement 2040 in expanded state. When the fixation elements are in theirexpanded states, the force expanded outwardly presses the fixationelements against the tissue into which they are applied, holding them inplace. The surfaces of the fixation elements 2030, 2040 may be roughenedor have gripping elements, such as barbs or protrusions to aid infixation in tissue. The elongated central region 2000 may be tubular andhollow, or it may be solid, or it may have passageways or channelsthrough which fluid may flow. Engagement member (not shown in FIG. 14)is positioned at proximal end of central region 2000.

1. An implantable device for control over the size of emphysematousbullae in a lung, comprising: i. an elongated central region having afixed axial length; ii. a first end including a first anchor; iii. asecond end including a second anchor.
 2. The implantable device of claim1, wherein said central region is generally cylindrical in shape.
 3. Theimplantable device of claim 1, wherein said central region issubstantially straight along a central axis.
 4. The implantable deviceof claim 1, wherein said first anchor comprises a self-curling anchorregion such that in the absence of force, the first anchor region iscurled to a degree of curvature from about 30 degrees to about 180degrees.
 5. The implantable device of claim 1, wherein said secondanchor comprises a self-curling anchor region such that in the absenceof force, the second anchor region is curled to a degree of curvaturefrom about 30 degrees to about 180 degrees.
 6. The implantable device ofclaim 1, wherein said first anchor comprises a hinged arm extending in adirection substantially towards said second end.
 7. The implantabledevice of claim 1, wherein said second anchor comprises a hinged armextending in a direction substantially towards said first end.
 8. Theimplantable device of claim 1, wherein the ends of said first and/orsecond anchors are non-piercing.
 9. The implantable device of claim 1,wherein the ends of said first and/or second anchors comprise a hook, aring, a ball, an ellipsoid, a disk, or a tab.
 10. The implantable deviceof claim 1, wherein said first anchor comprises more than one anchorregion.
 11. The implantable device of claim 1, wherein said secondanchor comprises more than one anchor region.
 12. An assembly comprisingthe implantable device of claim 1 and a deployment device.
 13. Theassembly of claim 12, wherein said deployment device comprises acatheter.
 14. The assembly of claim 13, wherein said catheter comprisesa positioning member to position said implantable device.
 15. Theassembly of claim 14, wherein said catheter comprises a connector deviceto releasably engage with the implantable device.
 16. A method ofdelivering the implantable device of claim 1, comprising the steps ofaligning said first anchor to a target site while said implantabledevice is at least partially placed within a deployment device,deploying said first anchor such that it engages a first region of thelung, pulling said first anchor in a proximal direction towards thesecond anchor, and releasing said second anchor such that it engages asecond region of the lung.
 17. The method of claim 16, furthercomprising the step of obtaining an image of a diseased area of a targetsite.
 18. The method of claim 16, wherein said target site is a regionof a lung.
 19. The method of claim 16, wherein said step of releasingsaid second anchor comprises separating an engagement member on saidimplantable device from an attachment on said deployment device.
 20. Amethod of delivering an implantable device into a diseased region of alung, comprising the steps of: i. Guiding a delivery device to a targetsite within said lung, wherein said target site is an emphysematousbullae in a lung, and wherein said delivery device contains animplantable device compressed within a distal end of said deliverydevice, said implantable device comprising: (a) an elongated centralregion having a fixed axial length; (b) a distal end including a distalexpandable anchor; and (c) a proximal end including a proximalexpandable anchor; ii. releasing said distal end of said implantabledevice from said delivery device, thereby expanding said distalexpandable anchor within said target site; iii. pulling said implantabledevice proximally, wherein said pulling causes the distal expandableanchor to pull tissue at said target site proximally; iv. releasing saidproximal end of said implantable device from said delivery device,thereby expanding said proximal anchor within said target site; v.releasing said implantable device from said delivery device.